This invention relates to link assemblies which are automatically separable upon the occurrence of a predetermined event, and more particularly to a separable link in a strap arrangement wherein the link is adapted to be separable by means of a self-contained explosive charge.
In many applications where connecting belts or safety belts are employed, it frequently is desirable to provide for automatic separation of the belt upon the happening of a predetermined condition, assuming the wearer of the belt is for some reason, such as injury or incapacity, unable to effect separation thereof.
For example, when pilots or other aircraft crew members parachute from a plane over a body of water, it is essential that the straps which connect the parachute to the strap harness worn by the individual be readily separable. Various types of manually operated release mechanisms have been devised, but each requires that the wearer be conscious and be able manually to effect the desired release. If the individual is unconscious or is otherwise injured to the extent that he cannot manually effect release, automatic release means can be provided to insure release of the parachute when the wearer has entered the water. For example, in U.S. Pat. No. 3,744,102 there is disclosed a strap release mechanism which operates automatically to release the strap connection. A pressurized gas is provided to the link element to actuate a piston which moves in such a fashion as to cause link connecting pins to move inwardly to thereby permit the separation.
In U.S. Pat. No. 4,023,846 there is disclosed a link release mechanism wherein a movable bolt which provides the connection between adjacent link members is caused to move to a position wherein the two connecting links become separable. The movement of the bolt is accomplished by pressurized gas which is provided by an explosive cartridge which, in turn, is activated by a suitable sensor to sense when immersion in water takes place.
A number of the prior art devices are relatively bulky and require external sources of pressurized gas. Those in which a source of gas is provided in the form of an explosive cartridge frequently include a number of movable parts and also involve the use of shear pins to properly position the parts in their operating mode prior to actuation of the release means.
It is an object of the present invention to overcome the above-described difficulties and shortcomings and to provide an improved separable link which is self-contained, which includes a minimum of moving or movable parts, and which is relatively easy to manufacture and to install.